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rdb.h 3.5 KB

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  1. /*
  2. * replay-database.h
  3. *
  4. * interface for a replay database for packet security
  5. *
  6. * David A. McGrew
  7. * Cisco Systems, Inc.
  8. */
  9. /*
  10. *
  11. * Copyright (c) 2001-2017, Cisco Systems, Inc.
  12. * All rights reserved.
  13. *
  14. * Redistribution and use in source and binary forms, with or without
  15. * modification, are permitted provided that the following conditions
  16. * are met:
  17. *
  18. * Redistributions of source code must retain the above copyright
  19. * notice, this list of conditions and the following disclaimer.
  20. *
  21. * Redistributions in binary form must reproduce the above
  22. * copyright notice, this list of conditions and the following
  23. * disclaimer in the documentation and/or other materials provided
  24. * with the distribution.
  25. *
  26. * Neither the name of the Cisco Systems, Inc. nor the names of its
  27. * contributors may be used to endorse or promote products derived
  28. * from this software without specific prior written permission.
  29. *
  30. * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  31. * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  32. * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  33. * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  34. * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
  35. * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  36. * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  37. * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  38. * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  39. * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  40. * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  41. * OF THE POSSIBILITY OF SUCH DAMAGE.
  42. *
  43. */
  44. #ifndef REPLAY_DB_H
  45. #define REPLAY_DB_H
  46. #include "integers.h" /* for uint32_t */
  47. #include "datatypes.h" /* for v128_t */
  48. #include "err.h" /* for srtp_err_status_t */
  49. #ifdef __cplusplus
  50. extern "C" {
  51. #endif
  52. /*
  53. * if the ith least significant bit is one, then the packet index
  54. * window_end-i is in the database
  55. */
  56. typedef struct {
  57. uint32_t window_start; /* packet index of the first bit in bitmask */
  58. v128_t bitmask;
  59. } srtp_rdb_t;
  60. #define rdb_bits_in_bitmask (8 * sizeof(v128_t))
  61. /*
  62. * srtp_rdb_init
  63. *
  64. * initalizes rdb
  65. *
  66. * returns srtp_err_status_ok on success, srtp_err_status_t_fail otherwise
  67. */
  68. srtp_err_status_t srtp_rdb_init(srtp_rdb_t *rdb);
  69. /*
  70. * srtp_rdb_check
  71. *
  72. * checks to see if index appears in rdb
  73. *
  74. * returns srtp_err_status_fail if the index already appears in rdb,
  75. * returns srtp_err_status_ok otherwise
  76. */
  77. srtp_err_status_t srtp_rdb_check(const srtp_rdb_t *rdb, uint32_t rdb_index);
  78. /*
  79. * srtp_rdb_add_index
  80. *
  81. * adds index to srtp_rdb_t (and does *not* check if index appears in db)
  82. *
  83. * returns srtp_err_status_ok on success, srtp_err_status_fail otherwise
  84. *
  85. */
  86. srtp_err_status_t srtp_rdb_add_index(srtp_rdb_t *rdb, uint32_t rdb_index);
  87. /*
  88. * the functions srtp_rdb_increment() and srtp_rdb_get_value() are for use by
  89. * senders, not receivers - DO NOT use these functions on the same
  90. * srtp_rdb_t upon which srtp_rdb_add_index is used!
  91. */
  92. /*
  93. * srtp_rdb_increment(db) increments the sequence number in db, if it is
  94. * not too high
  95. *
  96. * return values:
  97. *
  98. * srtp_err_status_ok no problem
  99. * srtp_err_status_key_expired sequence number too high
  100. *
  101. */
  102. srtp_err_status_t srtp_rdb_increment(srtp_rdb_t *rdb);
  103. /*
  104. * srtp_rdb_get_value(db) returns the current sequence number of db
  105. */
  106. uint32_t srtp_rdb_get_value(const srtp_rdb_t *rdb);
  107. #ifdef __cplusplus
  108. }
  109. #endif
  110. #endif /* REPLAY_DB_H */